noun 下载 🔗分享 天然碱，泡碱。 Native sodium carbonate; natron. Examples : "The ancient Egyptians used niter, gathered from dry lake beds, to help preserve mummies. " 古埃及人使用从干燥湖床采集的天然碱（泡碱）来帮助保存木乃伊。 chemistry mineral substance geology 与AI对话词汇游戏阅读练习
noun 下载 🔗分享 硝石，火硝 A mineral form of potassium nitrate (saltpetre) used in making gunpowder. Examples : "The old chemistry book described how niter, found in certain caves, was a key ingredient in making gunpowder for cannons. " 这本旧化学书描述了如何在某些洞穴中发现的硝石（火硝），是制造大炮火药的关键成分。 mineral substance chemistry geology weapon material 与AI对话词汇游戏阅读练习
